1/*-
2 * Copyright (c) 1994 Christos Zoulas
3 * Copyright (c) 1995 Frank van der Linden
4 * Copyright (c) 1995 Scott Bartram
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 *	from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: stable/11/sys/compat/linux/linux_util.c 346819 2019-04-28 13:23:52Z dchagin $");
34
35#include "opt_compat.h"
36
37#include <sys/param.h>
38#include <sys/bus.h>
39#include <sys/fcntl.h>
40#include <sys/lock.h>
41#include <sys/malloc.h>
42#include <sys/kernel.h>
43#include <sys/linker_set.h>
44#include <sys/mutex.h>
45#include <sys/namei.h>
46#include <sys/proc.h>
47#include <sys/sdt.h>
48#include <sys/syscallsubr.h>
49#include <sys/systm.h>
50#include <sys/vnode.h>
51
52#include <machine/stdarg.h>
53
54#include <compat/linux/linux_util.h>
55
56MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
57MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
58MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
59MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
60
61const char      linux_emul_path[] = "/compat/linux";
62
63/*
64 * Search an alternate path before passing pathname arguments on to
65 * system calls. Useful for keeping a separate 'emulation tree'.
66 *
67 * If cflag is set, we check if an attempt can be made to create the
68 * named file, i.e. we check if the directory it should be in exists.
69 */
70int
71linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
72    char **pbuf, int cflag, int dfd)
73{
74	int retval;
75
76	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
77	    cflag, dfd);
78
79	return (retval);
80}
81
82void
83linux_msg(const struct thread *td, const char *fmt, ...)
84{
85	va_list ap;
86	struct proc *p;
87
88	p = td->td_proc;
89	printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm);
90	va_start(ap, fmt);
91	vprintf(fmt, ap);
92	va_end(ap);
93	printf("\n");
94}
95
96struct device_element
97{
98	TAILQ_ENTRY(device_element) list;
99	struct linux_device_handler entry;
100};
101
102static TAILQ_HEAD(, device_element) devices =
103	TAILQ_HEAD_INITIALIZER(devices);
104
105static struct linux_device_handler null_handler =
106	{ "mem", "mem", "null", "null", 1, 3, 1};
107
108DATA_SET(linux_device_handler_set, null_handler);
109
110char *
111linux_driver_get_name_dev(device_t dev)
112{
113	struct device_element *de;
114	const char *device_name = device_get_name(dev);
115
116	if (device_name == NULL)
117		return (NULL);
118	TAILQ_FOREACH(de, &devices, list) {
119		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
120			return (de->entry.linux_driver_name);
121	}
122
123	return (NULL);
124}
125
126int
127linux_driver_get_major_minor(const char *node, int *major, int *minor)
128{
129	struct device_element *de;
130	unsigned long devno;
131	size_t sz;
132
133	if (node == NULL || major == NULL || minor == NULL)
134		return (1);
135
136	sz = sizeof("pts/") - 1;
137	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
138		/*
139		 * Linux checks major and minors of the slave device
140		 * to make sure it's a pty device, so let's make him
141		 * believe it is.
142		 */
143		devno = strtoul(node + sz, NULL, 10);
144		*major = 136 + (devno / 256);
145		*minor = devno % 256;
146		return (0);
147	}
148
149	sz = sizeof("dri/card") - 1;
150	if (strncmp(node, "dri/card", sz) == 0 && node[sz] != '\0') {
151		devno = strtoul(node + sz, NULL, 10);
152		*major = 226 + (devno / 256);
153		*minor = devno % 256;
154		return (0);
155	}
156	sz = sizeof("dri/controlD") - 1;
157	if (strncmp(node, "dri/controlD", sz) == 0 && node[sz] != '\0') {
158		devno = strtoul(node + sz, NULL, 10);
159		*major = 226 + (devno / 256);
160		*minor = devno % 256;
161		return (0);
162	}
163	sz = sizeof("dri/renderD") - 1;
164	if (strncmp(node, "dri/renderD", sz) == 0 && node[sz] != '\0') {
165		devno = strtoul(node + sz, NULL, 10);
166		*major = 226 + (devno / 256);
167		*minor = devno % 256;
168		return (0);
169	}
170	sz = sizeof("drm/") - 1;
171	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
172		devno = strtoul(node + sz, NULL, 10);
173		*major = 226 + (devno / 256);
174		*minor = devno % 256;
175		return (0);
176	}
177
178	TAILQ_FOREACH(de, &devices, list) {
179		if (strcmp(node, de->entry.bsd_device_name) == 0) {
180			*major = de->entry.linux_major;
181			*minor = de->entry.linux_minor;
182			return (0);
183		}
184	}
185
186	return (1);
187}
188
189char *
190linux_get_char_devices()
191{
192	struct device_element *de;
193	char *temp, *string, *last;
194	char formated[256];
195	int current_size = 0, string_size = 1024;
196
197	string = malloc(string_size, M_LINUX, M_WAITOK);
198	string[0] = '\000';
199	last = "";
200	TAILQ_FOREACH(de, &devices, list) {
201		if (!de->entry.linux_char_device)
202			continue;
203		temp = string;
204		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
205			last = de->entry.bsd_driver_name;
206
207			snprintf(formated, sizeof(formated), "%3d %s\n",
208				 de->entry.linux_major,
209				 de->entry.linux_device_name);
210			if (strlen(formated) + current_size
211			    >= string_size) {
212				string_size *= 2;
213				string = malloc(string_size,
214				    M_LINUX, M_WAITOK);
215				bcopy(temp, string, current_size);
216				free(temp, M_LINUX);
217			}
218			strcat(string, formated);
219			current_size = strlen(string);
220		}
221	}
222
223	return (string);
224}
225
226void
227linux_free_get_char_devices(char *string)
228{
229
230	free(string, M_LINUX);
231}
232
233static int linux_major_starting = 200;
234
235int
236linux_device_register_handler(struct linux_device_handler *d)
237{
238	struct device_element *de;
239
240	if (d == NULL)
241		return (EINVAL);
242
243	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
244	if (d->linux_major < 0) {
245		d->linux_major = linux_major_starting++;
246	}
247	bcopy(d, &de->entry, sizeof(*d));
248
249	/* Add the element to the list, sorted on span. */
250	TAILQ_INSERT_TAIL(&devices, de, list);
251
252	return (0);
253}
254
255int
256linux_device_unregister_handler(struct linux_device_handler *d)
257{
258	struct device_element *de;
259
260	if (d == NULL)
261		return (EINVAL);
262
263	TAILQ_FOREACH(de, &devices, list) {
264		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
265			TAILQ_REMOVE(&devices, de, list);
266			free(de, M_LINUX);
267
268			return (0);
269		}
270	}
271
272	return (EINVAL);
273}
274